How does Assistant get the message back

I have tried a few time with asking question for a specific PDF using Assistant in the playground.
and I monitor the logs to see what exactly happens in the background in terms of API calls.
However, I don’t understand how those final message were got back from the API.
as you can see from the image,

image

After running the thread, we are constantly calling the getStatus and getRunSteps API until the status is completed. however, none of the API return the final message (the Answer). Am I missing anything here? Also, why do we call getRunSteps if the status is not completed? isn’t that unnessary?

Apparently, the logs for the Playground didn’t show the full API logs because after I created a new Assistant, i can see it’s calling GetMessage API to get the answer back. However, its not visable in my previous Assistant run.